Chevy small block identification

I have a small block Chevy in my pick-up with the following casting numbers, can anyone help identify it's origin? Block Casting #3731548, Engine Date Stamp T312F, Head Casting #3731554.

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1957 283......http://www.nastyz28.com/sbchevy/sblock.html

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That is with "No side motor mounts"... http://www.mortec.com/castnum.htm

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JW spilled my beer when they jumped on the table and proclaimed in

Sticks, the site JW references above is a good place for GM head/block casting numbers...if you run across a future need.
It's the place where I found out my former neighbor was a moron when he said a 307 was a 350. :)
NOI
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